The present invention relates to fiber-to-the-home (FTTH) optical transmission systems and more particularly to an FTTH optical receiver used in such system having gain control and a remote enable for receiving and processing video, voice, and data optical signals.
In recent years there has been a great deal of interest in the transmission of video, voice, and data signals via optical fiber that is pulled to the home, i.e., fiber-to-the-home (FTTH) systems. Traditionally, cable operators have provided video and data signals over a hybrid fiber/coaxial cable (HFC) system. In this manner, optical signals are sent via optical fiber for transmission over longer distances. The optical signals are later converted to radio frequency (RF) signals for further transmission over coaxial cable before entering the home. Moreover, telephone operators have traditionally provided voice and data signals via optical fiber that is pulled to the home, and the signals then enter the home via twisted pair cable. When Congress passed the 1996 Telecommunications Act to promote competition in the telecommunications industry, a small number of cable and telephone operators expanded their services to provide numerous signals (e.g., video, voice, and data) over their system infrastructure. A few larger cable operators have been successful in providing telephony along with video and data signals, but they have deployed traditional telephony circuit-switched platforms due to the significantly different delivery requirements of the video signals compared with the delivery requirements of the voice and data signals. More recently, cable operators that wish to provide telephony signals are delaying the project as the traditional circuit-switched technology migrates to Internet Protocol (IP) based telephony. As a result, there has not been as much immediate incentive for the traditional cable operator to upgrade their existing HFC system to an FTTH system. Conversely, traditional telephone operators continue pulling fiber closer to the curb (i.e., fiber-to-the-curb (FTTC)) or home to deliver voice and data signals. They have not been, however, able to effectively deliver video services over the FTTC or FTTH system infrastructure, once again, due to the significant difference in system requirements for the delivery of video signals.
As the demand for video, voice, and data services continues to grow, however, optical fiber solutions continue to gain momentum over the traditional HFC and telephony systems for both the cable and telephone operators. In addition, there are several advantages for utilizing optical fiber that is pulled closer to the home for providing cable and telephone services. Advantageously, optical fiber systems typically enjoy a high signal quality; lower maintenance and easier troubleshooting; a low attenuation rate; and easy system expansion, to name but a few. Conversely, some of the disadvantages with an HFC system are the limited bandwidth; limited protocol; and that the HFC system must be upgraded for expandability.
What is needed, therefore, is an optical receiver that is capable of offering a complete package of broadband services including video, voice, and data signals over a fiber-to-the-home (FTTH) system. The FTTH optical receiver needs to provide not only voice and data signals in the conventional telephony manner, but additionally, provide video signals without compromising the quality in comparison with the quality of the signal transmitted by the conventional HFC system.